1. Field of the Invention
The present invention relates to a zoom lens and an imaging apparatus. More specifically, the present invention relates to a zoom lens suitably used for cameras such as video cameras and digital still cameras, which are configured to detect light by image sensors of these cameras and are equipped with so-called anti-shaking functions adaptable to realize stabilization of a taken images in such a manner as to perform, by shifting a part of lens groups included in the zoom lens to have a component perpendicular with respect to an optical axis, optical correction of a taken-image blur resulting from oscillations of the zoom lens so as to obtain a blur free image, as well as to an imaging apparatus involving use of the zoom lens.
2. Description of Related Art
Blurring in an image is caused by camera shaking, such as those attributable to shutter releases at the time of image taking or those resulting from application of oscillations to an image taking system when an image taking is carried out on a moving object, such as automobiles. One means of correcting an image blurring caused by a camera shake as described above is an optical camera-shake correcting system of a type that provides shifting a part of lens groups included in a lens system in directions approximately perpendicular to an optical axis, shifting an image position to correct the image blur, and allowances for correction of optical performance degradation occurring in association with image position shift.
Specifically, a technology disclosed in Japanese Patent Application Publication No. 2006-98963 (Patent Document 1) is known. A zoom lens according to the Patent Document 1 includes an array of first to fourth lens groups, which are of positive, negative, positive, and positive refractive power lens groups, and a fifth lens group composed of a negative part group having a negative refractive power and a positive part group having a positive refractive power, wherein anti-shaking is performed by shifting the above positive part group in directions approximately perpendicular to an optical axis.